The festival commemorates the 81st anniversary of 1934’s “Bloody Thursday” when two workers were shot and killed in San Francisco for supporting the longshoremen and maritime workers strike. The incident brought about the San Francisco General Strike.

In 2015 the festival also marks the 100th anniversary of the death of labor activist, songwriter, and member of the Industrial Workers of the World, Joe Hill, and the 150th anniversary of the Buildomg of Transcontinental Railway by Chinese workers.